APPLE INSIDER
Apple is working on two-coil wireless charging technology for an iPhone battery case without using the Lightning connector, something that would be necessary for a completely wireless iPhone.
Current Smart Battery Case models only charge wirelessly. They transfer power to an iPhone via Lightning.Current Smart Battery Case models can charge themselves wirelessly, but use a built-in Lightning connector to power the iPhone they’re attached to. That could prove to be a problem on a completely wireless iPhone.
Source: APPLE INSIDER